Trader Daniel Leporin works on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

Trader Michael Milano, right, listens to specialist Mark Fitzgerald as they work on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

Trader Patrick Casey, right, works on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

Trader James Riley works on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

Traders Robert Arciero, left, and Frederick Reimer work on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

Trader Edward Curran works on the floor of the New York Stock Exchange, Monday, March 20, 2017. U.S. stocks are opening slightly lower, led by losses in banks after Britain announced it will formally trigger the process of leaving the European Union. (AP Photo/Richard Drew)

TOKYO (AP) — Asian shares were mixed in lackluster trading on Tuesday, as markets searched for a dominant theme, weighing currency fluctuations, signs of growing protectionism and other uncertainties.

WHAT'S AHEAD: European markets mostly fell overnight after the British government said it will formally begin the process of leaving the European Union next week. Investors also are watching for elections in France and a European Central Bank meeting, both next month, while legislators in the U.S. debate the proposed Republican-backed health care law.

WALL STREET: The Standard & Poor's 500 index lost 0.2 percent to 2,373.47. The Dow Jones industrial average was almost unchanged at 20,905.86. The Nasdaq composite was also flat, at 5,901.53.

THE QUOTE: "Markets are hard pressed to look for new and enduring themes. And none emerge; at least not compellingly so," said Vishnu Varathan, of the Singapore Treasury Division of Mizuho Bank.

TRADE WORRIES: Finance ministers and central bankers from the Group of 20 major economies dropped a pledge to eschew protectionism in a statement Saturday. The move came after pressure from the U.S. During his campaign President Donald Trump promised to rewrite trade deals, and he ditched the Trans-Pacific Partnership after taking office.

ENERGY: Benchmark U.S. crude added 19 cents to $49.10 a barrel in New York. Brent crude, used to price international oils, rose 20 cents to $51.82 a barrel in London.

CURRENCIES: The dollar rose to 112.74 yen from 112.53 yen. The euro slipped to $1.0758 from $1.0760.

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AP Markets Writer Marley Jay contributed to this report. He can be reached at http://twitter.com/MarleyJayAP